1. Field of the Invention
The present invention relates to the field of manufacturing mass-fabricated items. More specifically, it relates to a system and method for automating a series of post-manufacturing processing steps for mass-fabricated items that are provided with three-dimensional codes formed therein, such as molds used to fabricate plastic dental aligners.
2. Background of the Invention
In the production of mass-customized items, the ability to identify individual items is important. One example of mass-customized items is plastic orthodontic alignment appliances, as described, for example, in U.S. Pat. No. 5,975,893 and U.S. Patent Application Publication 2005/0082703, both of which are commonly assigned to the assignee of the subject invention, and the disclosures of which are both incorporated herein by reference. Other examples are prosthetic devices, form-fitting hearing aids, and athletic equipment (such as pads and protectors).
Plastic orthodontic appliances, of the type disclosed in the above-referenced documents, are made as a set of incremental position adjustment appliances that are used to realign or reposition a patient's teeth. The series of incremental position adjustment appliances is custom made for each patient during the fabrication process.
The fabrication process starts with a practitioner (e.g., a dentist) making impressions or casts of the upper and lower dental arches of a patient. The impressions or casts are then sent by the dentist to an orthodontic appliance manufacturing facility. The manufacturing facility creates a treatment file from the impressions or casts that includes the treatment information for the patient. Treatment information includes the number of stages (i.e. each appliance in the series of incremental position adjustment appliances represents a stage) for both the upper and lower jaws that are required for repositioning the patient's teeth, as well as how the patient's teeth move during each stage. The treatment file is then sent to the dentist for approval. Upon approval, the manufacturing facility generates 3D CAD models or images of molds for making the appliances using the treatment file, and then creates the molds using a rapid prototyping process, such as, for example, stereolithography (SLA). The molds are then used to fabricate the appliances. Because each aligner is associated with a unique mold on which the aligner is fabricated, for the purposes of this disclosure, the molds themselves are considered to be mass-fabricated custom items.
The SLA process is performed in SLA machines that build polymeric molds from the CAD images or models. Typically, a mass-customized item is identified by encoding item identification data into a multi-dimensional barcode and using an SLA apparatus to make the part with the multi-dimensional (i.e., three-dimensional) barcode embedded therein. See, for example, U.S. Pat. No. 6,976,627, commonly assigned to the assignee of the subject invention, the disclosure of which is incorporated herein by reference.
Ink is manually applied to the barcode with a marker so that a barcode reader can accurately read the information encoded therein. Next, a release agent is manually sprayed onto the molds so that the aligners can be easily separated from the molds. These process steps involve laborious manual operations, and therefore entail substantial costs and time to produce the items. Accordingly, there is a need for an efficient system and method to improve productivity by automating as many of these steps as possible.